1. Field of the Invention
The present invention relates to lock down devices, and more particularly pertains to a trailer lock down device for securing trailers such as a boat trailer, a utility trailer or a travel trailer in a selected location. These forms of trailers must frequently be left unattended in a particular location. Additionally, it is desirable to maintain these trailers in a level orientation when parked. Frequently, these trailers have a relatively large amount of tongue weight which makes it difficult to lift the trailer tongue for mounting on a vehicle. In order to overcome these problems, the present invention provides a trailer lock down device including a hydraulic jack for moving the trailer tongue to a level position.
2. Description of the Prior Art
Various types of lock down devices are known in the prior art. A typical example of such a lock down device is to be found in U.S. Pat. No. 3,937,437, which issued to N. Stewart on Feb. 10, 1976. This patent discloses an anchoring apparatus for use in anchoring structures to the ground by use of elongated flexible straps. The anchoring apparatus has a lower ground engaging portion which is embedded in the ground below ground level. U.S. Pat. No. 4,074,519, which issued to C. Garrett on Feb. 21, 1978, discloses a swivel shackle for connection to a tension member, whereby a force can be applied in any direction within a hemisphere centered about an attachment point. U.S. Pat. No. 4,487,537, which issued to H. Morse on Dec. 11, 1984, discloses a drum tie-down apparatus for securing containers in an upright position to a floor or platform of a transportation vehicle. U.S. Pat. No. 4,592,686, which issued to G. Andrews on June 3, 1986, discloses a tie-down swivel including a cooperating bushing and stud to transfer variable loadings to a base. U.S. Pat. No. 4,630,982, which issued to J. Fenner on Dec. 23, 1986, discloses a cargo tie-down system in which a receptacle having a socket is incorporated into a floor of a vehicle cargo department.
While the above mentioned devices are directed to lock down devices, none of these devices disclose a trailer lock down device which utilizes a hydraulic jack to secure the tongue of a trailer in a level position. Additional features of the present invention, not contemplated by the aforesaid prior art devices include the provision of an open ended locking box formed by two hingedly connected L-shaped members secured to a vertically adjustable shaft, the use of an elongated ground insertion anchor encapsulated in a concrete block and including a plurality of axially spaced radially extending flanges, and the use of a telescopic threaded extension member to provide a wide range of adjustment. Inasmuch as the art is relatively crowded with respect to these various types of lock down devices, it can be appreciated that there is a continuing need for and interest in improvements to such lock down devices, and in this respect, the present invention addresses this need and interest.